This bit specifies if the Will Message is to be Retained when it is published.
If the Will Flag is set to 0, then the Will Retain Flag MUST be set to 0.
If the Will Flag is set to 1:
If Will Retain is set to 0, the Server MUST publish the Will Message as a non-retained message.
If Will Retain is set to 1, the Server MUST publish the Will Message as a retained message
This bit specifies if the Will Message is to be Retained when it is published.
If the Will Flag is set to 0, then the Will Retain Flag MUST be set to 0. If the Will Flag is set to 1: If Will Retain is set to 0, the Server MUST publish the Will Message as a non-retained message. If Will Retain is set to 1, the Server MUST publish the Will Message as a retained message